Variably displaced regulated-voltage power supply



May 15, 1956 R. c. PAULSEN 2 9 VARIABLY DISPLACED REGULATEDVOLTAGE POWERSUPPLY Original Filed May 26, 1951 2 Sheets-Sheet l FIGJ INVENTOR.

ROBERT C. PAULSEN ATTORNEY May 15, 1956 R. c. PAULSEN VARIABLY DISPLACEDREGULATED-VOLTAGE POWER SUPPLY 2 Sheets-Sheet 2 Original Filed May 26,1951 INVENTOR ROBERT C. PAULSEN BY m ATTOR 0+ n mow m A 3 C mww m8 NwNKWM. 3N vmm 6N M TNN A N w wmm NN o N m3 mm 08 W .\m@ ww mmw m8 5N mwm ENEN EN EN \oa EN wmN NEY United States Patent VARIABLY DISPLACEDREGULATED-VOLTAGE POWER SUPPLY Robert C. Paulsen, West Caldwell, N. 1.,assignor to International Business Machines Corporation, New York, N.Y., a corporation of New York Original application May 26, 1951, SerialNo. 228,432, now Patent No. 2,717,994, dated September 13, 1955. Dividedand this application February 7, 1952, Serial N o. 27 0,413

Claims. (Cl. 323-22) This invention relates to regulated power supplies,and more particularly to power supplies adapted to provide a regulatedvoltage which is variably displaced from a given level, as for exampleground.

This application is a division of application Serial No. 228,432 filedMay 26, 1951, and now Patent 2,717,994 issued September 13, 1955. Theparent application relates to measuring and indicating systems and moreparticularly to improved means for measuring and indicating ormanifesting the value of a variable quantity such as an electricalpotential or a physical displacement.

A principal object of the present invention is to provide an improvedregulated power supply.

Another object of the present invention is to provide a source ofregulated voltage which may have a variable displacement with respect toa given level.

In accordance with the present invention, there is provided a regulatedpower supply which comprises the combination of a plurality ofstructural elements. These elements include a source of fixed potentialhaving output terminals, plural impedance elements, a voltage-regulatingdevice connected in series with the impedance elements across the fixedsource, a source of variable potential having first and secondterminals, the first terminal being connected to a first output terminalof the fixed source, means associated with the second terminal forvarying the potential drop across a first of the impedance elements as afunction of the variable potential, and means for utilizing thepotential drop between the second terminal and the junction of a secondof the impedance elements and the voltage-regulating device.

Other objects and features of the present invention will be pointed outin the following description and claims and illustrated in theaccompanying drawings, which disclose, by way of example, the principleof the invention and the best mode, which has been contemplated, ofapplying that principle.

In the drawings, in which like reference numerals designate likecomponents:

Fig. 1 is a schematic diagram of a power supply in accordance with thepresent invention; and

Fig. 2 is a schematic circuit diagram of the comparer unit disclosed inthe above-identified parent application and utilizing a power supply inaccordance with the present invention.

Referring to Fig. 1, there is shown a regulated power supply inaccordance with the present invention comprising a voltage-regulatingdevice 277, preferably comprising a tube of the cold-cathode type.Cathode 278 of tube 277 is connected through a first impedance elementor resistor 279 to ground. Anode 280 of tube 277 is connected through asecond impedance element or resistor 281 to a terminal 181 of a sourceof fixed potential (not shown), the other terminal of the potentialsource being grounded in accordance with conventional practice.

There is provided a source of variable potential having first and secondterminals, the first terminal being 239 of the pentode type.

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grounded as shown and the second terminal being designated by referencenumeral 244. Means are provided for varying the potential acrossresistor 27 9, these means comprising vacuum tube 282, preferablyarranged to operate as a. cathode follower. Cathode 283 of tube 282 isgrounded through resistor 27 9. Control electrode 284 of tube 282 isconnected to terminal 244 to which is applied a variable potential.Anode 286 of tube 282 is connected to terminal 281 of the source offixed potential. In operation, the potential difference between terminal244 and anode 280 of tube 277 remains substantially constant in spite ofwide variations in the potential of terminal 244 with respect to ground.

By way of example of means for utilizing this advantageous feature ofthe present invention, there is shown a vacuum tube 239, preferably ofthe tetrode type. Cathode 240 of tube 239 is grounded through a suitableresistor, control electrode 242 of tube 239 is connected to terminal244, and screen electrode 297 of tube 239 is connected to the junctionof second impedance element or resistor 281 and voltage-regulatingdevice 277. With the arrangement just described, it will be apparentthat the potential difference between control electrode 242 and screenelectrode 297 of tube 239 will remain substantially constant in spite ofwide variations of the potential between control electrode 242 andground. in this way, therefore, there has been provided in accordancewith the present invention a power supply which furnishes a regulatedvoltage having a variable displacement with respect to a given level, asfor example ground.

In order to bring out even more clearly how the advantages of thepresent invention may be utilized, there is shown in Fig. 2 of thedrawings a schematic circuit diagram of the comparer unit disclosed inthe above-identified parent application and utilizin a power supply inaccordance with the present invention. Referring to this figure,terminal 21%, comprising the output terminal of translator unit 14 (Fig.4 of the above-identified applica tion) is connected through a DPDTswitch 235 to a junction 236. Junction 236 is connected through an SPDTswitch 237 to anode 238 of an electron discharge device When switches235 and 237 are in the positions shown, the comparer unit is adapted toutilize an unknown variable quantity comprising an electrical potential.The system will first be described for operation with this type ofunknown input variable.

Cathode 240 of discharge device 239 is grounded through a resistor 241.Control electrode 242 is connected by a switch 243 either to inputterminal 244, to which the unknown potential is applied, or to ground.The potential of screen electrode 297 with respect to cathode 240 ismaintained substantially constant by an arrangement which will bedescribed later. Suppressor electrode 245 is connected to cathode 246.

It will be apparent that the potential of junction 236 with respect toground will be dependent upon the potential drop in resistors 1942t}9(Fig. 4 of the aboveidentified parent application) due both to the anodecurrents of the electron discharge devices of translator unit 14 and tothe anode current of electron discharge device 239, as well as to thepotential drop across resistor 241 due to the anode current of thelatter discharge device. An increase in the anode current of dischargedevice 239, such as might be caused by applying an input potentialbetween terminal 244 and ground, would tend to decrease the potentialbetween junction 236 and ground. A decrease in the conductivity of oneor more of the electron discharge devices of translator unit 14 wouldtend to cause an increase of potential at junction 236 with respect toground.

In order to utilize this efiect, there is provided a gaseous dischargedevice 246 having a cathode 247, a control electrode 248 and an anode249. Control electrode 248 is connected to junction 236 by a resistor250. A resistor 251 is connected between positive potential source 181and anode 249. For the purpose of maintaining substantially constant theanode-cathode potential of discharge device 246 so that it will fire atfixed control-electrode potential, there is provided a series networkbetween positive potential source 181 and ground comprising a resistor252'and an electron discharge device 253, preferably of the pentode typeand having a cathode 254 which is grounded through a resistor 255. Aresistor 256 is connected between cathode 247 of discharge device 246and anode 257 of discharge device 253. Control electrode 258 of device253 is grounded. Screen electrode 259 is connected through an adjustableresistor 260 to positive potential source 35, suitable additionalresistors 261 and 262 being provided and arranged as shown. Suppressorelectrode 263 is connected to cathode 254.

In operation, assuming first that counter unit 13 (Fig. 3 of theabove-identified parent application) is set at 0000 and that switch 243is in its right-hand position, resistor 260 is adjusted so that gaseousdevice 246 is barely extinguished. In other words, a small increase inthe potential of junction 236 with respect to ground would causedischarge device 246 to fire, with the result that a largepositive-going pulse is developed at cathode 247.

Now let it be assumed that switch 243 is in its lefthand position andthat an unknown potential has been applied to input terminal 244. Thiscauses the potential of junction 236 to decrease with respect to ground,so that control electrode 248 of discharge device 246 becomes morenegative with respect to cathode 247. As previously described, however,counter unit 13 has begun counting, so that the potential drop acrossresistors 194209 (Fig. 4 of the above-identified parent application)gradually decreases until the potential of junction 236 with respect toground rises sufiiciently to cause discharge device 246 to fire. Theresultant positive-going pulse at cathode 247 is applied by means of acapacitor 264 to control electrode 265 of an electron discharge device266, operating as a cathode follower and having its cathode 267 coupledby means of a capacitor 268 to lead 65. The resultant positive-goingpulse developed across cathode resistor 269 causes the closing of gateunit 11, as previously described in connection with Fig. 2, thusterminating the first portion of a complete operating cycle.

For the purpose of extinguishing discharge device 246 very shortly afterit fires, there is provided an electron discharge device 270 having acathode 271 connected to positive potential source 35. Control electrode272 of device 270 is connected through a resistor 273 and lead 274 tojunction 60 in gate trigger circuit 49 (Fig. 2 of the above-identifiedparent application). Control electrode 272 is bypassed to ground by acapacitor 275. Anode 276 of device 270 is connected to anode 249 ofdischarge device 246. When trigger circuit 49 is on during the measuringportion of each cycle, the left-hand portion of discharge device 50(Fig. 2 of the above-identified parent application) is non-conductiveand the potential of junction 60 is such that control electrode 272 issubstantially negative with respect to cathode 271 of discharge device270, so that this device is non-conductive. Upon the firing of dischargedevice 246, trigger circuit 49 is turned ofi, the left-hand portion ofdischarge device 50 becoming conductive and the potential of junction 60increasing sufiiciently to render discharge device 270 highlyconductive. The resultant additional current flow through resistor 251causes the potential of anode 249 of discharge device 246 to fall belowthat of cathode 247, thereby extinguishing this discharge device. Thiscon- 4 dition is maintained until the measuring portion of thesucceeding complete cycle is initiated.

In order that the anode current of discharge device 239 shall varylinearly with respect to changes in the unknown potential applied toterminal 244 and hence to its control electrode 242, it is necessarythat the potential of screen electrode 297 remain substantially constantwith respect to that of cathode 240 of discharge device 239. For thepurpose of accomplishing this, there is provided a voltage regulatortube 277, preferably of the cold-cathode type, having its cathode 278connected through an impedance element or resistor 279 to ground,

and having its anode 280 connected through an impedance element orresistor 281 to positive potential source 181. Screen electrode 297 ofdischarge device 239 is connected to anode 280 of regulator tube 277.There is also provided an electron discharge device 282, preferably ofthe tetrode type and having its cathode 283 connected to cathode 278 ofregulator tube 277. Control electrode 284 of discharge device 282 isconnected to control electrode 242 of discharge device 239. Screenelectrode 285 and anode 286 of discharge device 282 are connectedtogether and to positive potential source 181. Since discharge device282 operates as a cathode follower, variations in the potential of itscontrol electrode 284 due to changes in the unknown potential applied toinput terminal 244 are reflected linearly in the potential drop existingacross resistor 279 due to the anode current of discharge device 282.Thus the potential of cathode 283 varies directly as does that ofcathode 240 of discharge device 239. Because of the action of voltageregulator tube 277, its anode 280 remains at a substantially constantpotential above that of its cathode 278, with the result that thedifference in potential between screen electrode 297 and cathode 240 ofdischarge device 239 remains substantially constant, irrespective of themagnitude of the unknown potential applied between input terminal 244and ground. The provision of this arrangement for securing a linearrelationship between the unknown potential applied to terminal 244 andthe anode current of discharge device 239 constitutes an importantfeature of the present in vention.

While there have been shown and described and pointed out thefundamental novel features of the invention as applied to a preferredembodiment, it will be understood that various omissions andsubstitutions and changes in the form and details of the deviceillustrated and in its operation may be made by those skilled in theart, without departing from the spirit of the invention. It is theintention, therefore, to be limited only as indicated by the scope ofthe following claims.

What is claimed is:

1. In combination: a source of fixed potential having output terminals;plural impedance elements; a voltageregulating device connected inseries with said impedance elements across said fixed source; a sourceof variable potential having first and second terminals, said firstterminal being connected to a first output terminal of said fixedsource; means associated with said second terminal for varying thepotential drop across a first of said impedance elements as a functionof said variable potential; and means for utilizing the potential dropbetween said second terminal and the junction of a second of saidimpedance elements and said voltage-regulating device.

2. In combination: a source of fixed potential having output terminals;plural impedance elements; a voltageregulating device connected inseries with said impedance elements across said fixed source; a sourceof variable potential having first and second terminals, said firstterminal being connected to a first output terminal of said fixedsource; means associated with said second terminal for varying thepotential drop across a first of said impedance elements linearly as afunction of said variable potential; and means for utilizing thepotential drop between said second terminal and the junction of a secondof said impedance elements and said voltage-regulating device.

3. In combination: a source of fixed potential having output terminals;plural impedance elements; a voltageregulating device connected inseries with said impedance elements across said fixed source; a sourceof variable potential having first and second terminals, said firstterminal being connected to a first output terminal of said fixedsource; means associated with said second terminal for varying thepotential drop across a first of said impedance elements as a functionof said variable potential, said means comprising a cathode followerutilizing said first impedance element as its load impedance; and meansfor utilizing the potential drop between said second terminal and thejunction of a second of said impedance elements and saidvoltage-regulating device.

4. In combination: a source of fixed potential having output terminals;plural impedance elements; a voltageregulating device connected inseries with said impedance elements across said fixed source, saiddevice comprising a tube of the cold-cathode type; a source of variablepotential having first and second terminals, said first terminal beingconnected to a first output terminal of said fixed source; meansassociated with said second terminal for varying the potential dropacross a first of said impedance elements as a function of said variablepotential; and means for utilizing the potential drop between saidsecond terminal and the junction of a second of said impedance elementsand said voltage-regulating device.

5. In combination: a source of fixed potential having output terminals;plural impedance elements; a voltageregulating device connected inseries with said impedance elements across said fixed source, saiddevice comprising a tube of the cold-cathode type; a source of variablepotential having first and second terminals, said first terminal beingconnected to a first output terminal of said fixed source; meansassociated with said second ter minal for varying the potential dropacross a first of said impedance elements linearly as a function of saidvariable potential, said means comprising a cathode follower utilizingsaid first impedance element as its load impedance; and means forutilizing the potential drop between said second terminal and thejunction of a second of said impedance elements and saidvoltage-regulating device.

References Cited in the file of this patent UNITED STATES PATENTS2,407,853 Smith Sept. 17, 1946 FOREIGN PATENTS 514,835 Great BritainNov. 20, 1939

